Space Vacuum Investigations

Inaccessible-Non Repairable- Costly: The meaning of these words is absolute in the event of a complete failure of an orbiting spacecraft. Adequate design, or rather, minimizing chance of failure, challenges all scientists and engineers. Where experience has not been developed, the risk involved in a new application must be weighed against the consequence of a design failure. In space work, the spectrum of consequence is extremely wide. It ranges from loss of scientific data on one hand, to loss of life on the other.. There is little question that knowledge of the space environment and its effects must be determined to produce reliable spacecraft. Tests to prove the design must be performed with equipment capable of simulating the effects of the environment in which the design is to operate. This does not necessarily mean that the natural environment must be duplicated. The degree of environmental simulation that should be achieved depends primarily upon the significance of the physical effects it causes. The purpose of space vacuum simulation in an environmental test program should be accurately conceived and the testing phased to obtain maximum information from the limited samples available for test. This discussion is confined to some of the factors involved in simulating the effects of space vacuum environment. This survey is by no means complete, but will touch on some of the highlights in this field:
1. A description of the environment
2. The level of simulation necessary to evaluate its effects
3. Test equipment capability
4. Experience in test
5. Experience in orbit
6. Observations & future emphasis